Welding



Patented Dec. 1, 1925.

UNITED STAT-ESfPA-TENI omcE.

CHAD n. HUMPHRIES, .or KOKOMO, INDIANA, ASSIGNOR ro unrnins PROTECTION 00112., or KOKOMO, I1\ TDIANA, A CORPORATION OF.INDIANA.

WELDING.

No Drawing.

and useful Improvements in Welding, of

which thefollowing is a Specification.

This invention is designed to overcome the difficulty known as sputtering?,which is frequently encountered in the electric and acetylene or gas welding of iron and steel articles. Sputtering is a rather serious problem since it not only detracts from the appearance but also from the strength of the weld. While the exact .cause of sputter-'- ing is not known,.it has been observed that it is more pronounced in the case of gas welding than in the case of electric welding and also that it occurs more frequently with certain grades of steel than with other grades. "My observations have led me to I believe that sputteringis due largely to aa surface condition of the metal.

. tering, isnot definitely known. lhere isno The invention consists in treating" the metal surfaces to be welded with a strong solution of chromic acid for instance by dipping or local application. A suitable chro- 4 mic acid solution for this purpose may have for example the following composition:

Technical chrorhic acid, 2 pounds; sulfuric acid, A; ounce; water, 1 gallon.)

The effect of the-'chromicacid solution,

except that it forms a firmly adherent brownish-yellow filmon the surfaces of the metal to which it is applied and facilitates the welding. and eliminates the tendencyv to sputter of metals which previous to the treatment were diflicult to welddue to sput- 4 chromate.

, chromate on such' surfaces.

Application-filed August 31,1925. Serial 310358566.

doubt some chemicallaction between the 0 metal and the chromic acid solution and it seems probablethat the action of the'solution is to cleanthe metal surface of organicmatter and. to deposit 'over the surface of the clean metal a coatingof ferroso-ferric 4 In. practice the chromicacid solution is .appliedto the surfaces of the metal to' be welded either by'dip ing or by local 2. 1ication with-a brush or the like 'an'd i si al-fi lowedto dry or partially dry which occurs quicklyandis then welded by means of an acetylene or gas torch or by means 'ofJan electric welding rod in the usual way.

-Iclaimz- .1.- In' a process for weldingisurfacesof iron or steel articles, the step comprising the exposure of such surfaces to the action Ora chromicacid solution.

-2. A: process for-the. welding of surfaces of ironor steel articles, which comprises act- I ing upon such surfaces with 'asolution having substantially the following composition:

technical chromic acid 2 pou nds,; sulfuric facid' ounce and water 1 gallon. 3. In a process for welding'ironor steel surfaces, the step which comprises forming a. thin coating or' film offferroso-ferric 4. Process for gas and electric Welding 70 of iron andflsteel articles which consists in applying to the surfaces to be Welded a so- 4 lutlon of chromic acid, allowing-the surfaces to dry, and welding the surfaces.

In testimony whereof, I an; my signature.

I AD H. IFIUMPHRIES; 

